High-temperature fluorinations of uranium, neptunium, plutonium, americium and/or selected transition metal materials were carried out to investigate their volatile fluorides. Solid samples containing one or more of these elements were reacted with F2, CIF3, BF3 and/or O2 gases in platinum Knudsen cells at temperatures up to 800 °C. The volatile reaction products effusing from the cell were monitored with a quadrupole mass spectrometer. As anticipated, it was found that the ease of oxidation and the highest actinide oxidation state obtained decreased when proceeding from uranium to americium. Simultaneous treatment of two or more actinides allowed direct comparison of their behaviors under identical synthetic conditions. In addition to the expected binary fluorides, volatile oxyfluorides of uranium were observed. Synthetic experiments aimed at the preparation of higher valent, americium binary fluorides are discussed; it was not possible to identify AmF6.